As the marine hobby grows, new techniques, procedures, and
technology have made the husbandry of fishes, invertebrates, and other
organisms easier and easier. However, there is still one dreaded
scourge which occasionally attacks our prized fishes: Marine Ich. This
disease is probably the most common affliction that most hobbyists will
encounter. Although ich is such a common problem, there are probably as
many different approaches to treating it as there are hobbyists! The
focus of this article, however, will be on what I call a "two
front" approach to attacking ich. An approach that, although not
new, and by no means revolutionary- has a very high success rate.
Although there are a number of alternative therapies that have been
used to treat this disease, there are very few, in my opinion, that are
as effective (and successful!) as the approach that we will discuss
here. Let's begin with a quick review of what causes ich, the
symptoms of the illness, and a look at the life cycle of the parasite
that causes this dreaded affliction. By understanding the life cycle of
the parasite, we can develop an effective strategy to defeat the
disease.

The ugly little causative parasite of Marine Ich is the ciliated
protozoan, Cryptocaryonirritans (even the name sounds
bad!). The parasite has a rather simple life cycle, and has several
different phases during its life cycle when it is especially
vulnerable. The parasite, in its free swimming phase, locates a
suitable host (i.e.; your fishes!), and burrows into the host's
skin, gills, and fins, where it feeds on the fluids contained within
the host's body. For protection, the parasites form a thin cyst
over themselves. The cysts, which look a lot like grains of salt, are
usually the aquarist's first signal that the fish has contracted
the disease. The encysted parasites, called trophonts, remain
attached to their fish host for approximately 7 days until the
protozoan reaches maturity. Next, the protozoan leaves the host and
enters the water column as single cell, known as a tomont. The
tomont (or cyst) can swim for up to 18 hours before it attaches to a
suitable substrate, such as sand, rock, or the aquarium itself. Then,
the cells within the cysts divide, and form up to 200
"daughter" parasites, or tomites. This process, which
takes anywhere from 4 to 28 days, results in a new generation of free
swimming protozoans called theronts. The theronts must then
locate and inhabit a suitable host to complete their life cycle within
several hours, or they will die. It is during this free swimming phase
that the Cryptocaryon parasite is most vulnerable, and this is
the part of the life cycle when Marine Ich can be eradicated with a
relatively high degree of success.

The "Two Front" Approach To
Ich Treatment

My approach to defeating marine ich consists of battling the illness
on two "fronts": The "home front" (the main
aquarium), and the "battle front" (the treatment aquarium).
Attacking ich in the main system is a relatively simple processes, and
requires little more than patience and perseverance. The attack on the
"battle front" requires the use of readily available
medications. Let's look at what to do once ich manifests itself in
your aquarium.

Recognizing The Symptoms of Marine Ich

Usually, the first signs that a fish is infected with ich manifest
themselves shortly after the parasites lodge themselves in your
fishes' skin, gills, and fins. Affected fishes will usually show
small (up to 1mm) white spots throughout their bodies, which look very
similar to grains of salt. The fishes will often be seen attempting to
scratch themselves against rocks , corals, the substrate, or other
aquarium d?or, in an attempt to relieve themselves of the discomfort.
If left untreated, the parasites can attach themselves into the
fishes' gill tissues to the point where they can interfere with the
fishes' respiration. Obviously, the aquarist is advised to take
action as soon as possible to save the lives of his or her fishes.

After you have confirmed that you are, indeed dealing with Marine
Ich , your first move in attacking this disease is to remove all of the
fishes from the affected aquarium to a separate, bare aquarium of
appropriate size for a treatment and recovery regimen that will last
from 30 to 45 days. Did I just say "all of the fishes", even
if they are not showing signs of infection? Yes I did! Even though they
may not be displaying symptoms now, they have been exposed, and the
very real possibility of infection looms. If there is one thing I have
learned in my battles with this disease, it is that it's always
better to be safe then sorry! The first half of the treatment period
will involve treating the fishes with medication, and the second half
of the treatment period will allow the fishes to regain their strength
before being returned to their aquarium. By following this careful
treatment regimen, you will assure that your fishes have their best
chance to recover from this nasty disease.

I highly recommend performing a freshwater dip on each fish before
being placed in the treatment tank. The freshwater should be properly
buffered and heated to the same temperature as the tank that your
fishes have been residing in. Use of a non-toxic anti-bacterial agent,
such as Methylene Blue, is encouraged during the dip. Use enough
Methylene Blue to color the water a deep blue. The duration of the dip
should be from 3 to 5 minutes, depending on the tolerance of the
individual fish(es) being dipped. Keep a close eye on the fish during
the dip process, and be prepared to remove them to the treatment tank
quickly, should they show extreme distress during this process. The
freshwater dip is a standard part of the acclimation and quarantine
process at most public aquariums throughout the world, and is an
effective procedure that can reduce or eliminate many external
parasites, including Cryptocaryon. The reason that freshwater dips are
so successful is that the parasites simply cannot make the osmotic
"stretch" to freshwater as well as the fish can.

After the dip process has been completed, the fishes should be
placed in the treatment aquarium. The aquarium should have water
conditions (specific gravity, pH, etc) that approximate those in the
aquarium from which they came. Some hobbyists prefer to lower the
specific gravity in the treatment aquarium to 1.015 or less, a
procedure known as "hyposalinity". This technique is used for
many of the same reasons that the freshwater dip is performed. I
personally do not utilize this process, but it certainly has its
proponents.

Administer an over-the-counter copper sulphate preparation
(specifically formulated for aquarium use). Follow the
manufacturer's instructions concerning its use exactly as
instructed by the manufacturer. Always use a test kit to monitor the
concentration of copper in the water, in order to assure that
you're maintaining a proper therapeutic dosage. Be sure that you
replenish the copper as needed each time you change the water in the
treatment aquarium. Do not assume that your treatment tank has the
correct level of copper! You run the risk of diluting the copper to an
ineffective level, or possibly increasing it to a toxic level. I cannot
stress it enough-always test the copper level when using it to
treat disease. It literally could mean the difference between life or
death for your fishes. Enough said.

Since the Cryptocaryon parasite enters a free-swimming phase, when
it heads to the bottom of the aquarium after detaching from the fishes,
you may actually be removing some of these parasite cysts when you
siphon debris from the bottom of the treatment aquarium. Regular water
changes are a highly effective means of maintaining water quality
and removing some of these cysts. I recommend changing 5% of the
treatment aquarium's water volume twice a week during the treatment
period.

Long-term exposure to copper can be harmful to fishes. Tangs, in
particular, can suffer if they linger too long in copper-treated water.
They harbor beneficial digestive bacteria, which enable them to process
their food. These bacteria may be adversely affected by long-term
copper exposure. The idea here is to employ a one-to-two-week exposure
to the copper medication, and then reduce the copper level through
water changes (without replenishing the copper, of course) and
absorptive filter media, such as Poly Filter. If you are treating
fishes such as Centropyge angelfishes, which have a reputation for
copper sensitivity, you may want to utilize an aquarium medication
containing Formalin, instead of copper. The remainder of your fishes
stay in the treatment aquarium will be dedicated to providing them with
high-quality foods, good water quality, and careful observation. Use
this period of time to ascertain that your fishes are once again
healthy, and that no secondary infections have had the opportunity to
manifest themselves.

The Home Front

After removing your fishes to a "hospital" tank for
observation and treatment, you will have created a serious disruption
to the life cycle of the Cryptocaryon parasite. Your main system will
be running in a "fallow" state. Invertebrates may remain in
the display aquarium, as they are not susceptible to the illness, nor
are they thought to be a "vector" for the illness. In the
absence of hosts, most of the free-swimming theronts will perish . This
is where an understanding of the parasite's life cycle will pay
off. By letting your tank run "fallow", you will
significantly reduce the number of parasites remaining in the system,
which will make the likelihood of a new outbreak much less when your
fishes are "repatriated".

The fallow period will last a minimum of
one month. During the fallow period, do continue to perform routine
water changes and other maintenance tasks in the aquarium. Not only
will you be maintaining a cleaner system with fewer organics, but you
may actually be physically removing some of the encysted and
free-swimming parasites themselves from the system, particularly if you
siphon the substrate. Also, performing your routine maintenance
procedures on your tank during the fallow period, you help assure that
your newly-cured specimens will be returning to a clean, stable
aquarium environment.

After the fallow period, and after you have determined that your
fishes are once again in good health, you may return them back to their
aquarium. The procedure that I have outlined here is based upon
successful, tried-and-true methods used by countless private and
professional aquarists alike for years. None of the procedures are
radical or revolutionary, but they do work! Keep in mind, however, that
no treatment procedure, regardless of how well thought out or
comprehensive, can guarantee 100% effectiveness at eradicating this, or
any disease. As more research is done in the marine fish arena, no
doubt more comprehensive and effective treatment protocols may enter
the fray.

There are a few promising alternative treatment techniques for ich
that are being discussed with increasing frequency on marine hobby
internet message boards and in hobby publications. The use of garlic
extract to treat marine ich has received quite a bit of attention
lately, although its effectiveness is based largely on anecdotal
evidence, and has not been thoroughly studied to date. Garlic
proponents suggest that a substance contained in fresh garlic extract,
Allicin (Diallyl thiosulphate) acts as a "blocker" to
chemical cues used by the Cryptocaryon parasite to recognize its
potential host. Use of garlic extracts may prove to be more valuable as
a preventative, rather than a true "treatment" after the
disease has manifested itself in fishes. Hopefully, further research at
both the hobby and scientific level will yield further useful answers
on this topic.

Prevention

While we're on the subject of prevention, possibly one of the
most effective means of ich prevention is the regular use of a
quarantine period for all new fishes, before they are placed in the
main aquarium. A three to four week quarantine gives the aquarist
tremendous control, and allows the aquarist the opportunity to observe
his or her specimens without fear of transmitting possible illnesses to
the inhabitants of the main aquarium. Since many parasitic diseases,
including ich, manifest themselves after a few weeks, it simply
doesn't make sense to not quarantine your fishes. Proper use
of quarantine procedures will make a huge difference in your success as
an aquarist.

After initial quarantine of your newly-received fishes, the best
thing that you can do to prevent ich and other diseases from taking
over your aquarium is to provide a proper, stable environment for your
animals. Methods to achieve this include careful, sparse stocking of
animals, proper diet, and a regular, comprehensive maintenance and
testing regimen.

Rather than striving for a specific "number" on a test
kit, the aquarist should endeavor to maintain stability. This means
that if your tank temperature is 79 degrees Fahrenheit, you should do
all that you can to maintain that temperature on a consistent basis. If
your system runs at a specific gravity of 1.025, utilize top offs and
regular water changes to keep it that specific gravity. As you are no
doubt aware, the ocean is among the most stable environments on earth,
and most fishes have not evolved to tolerate rapid environmental
changes without incurring severe stress. And continuous stress can lead
to disease!

While we're on the subject of stress, it goes without saying
that few things contribute to greater stress in captive marine fishes
than an overcrowded, inappropriate mix of animals. For example,
maintaining small, docile fishes, such as Mandarins or Anthias with
aggressive, territorial, or fast-moving fishes such as Damselfishes,
Triggerfishes, and Groupers, is a recipe for disaster in the confines
of an aquarium. A fish that is subjected to harassment from its
tankmates will constantly hide, fail to eat properly, and generally
decline in health quite rapidly. The same goes for fishes that require
large amounts of space, such as tangs. When confined to an aquarium
that is too small, these fishes will display very "unnatural"
behaviors, such as "hyper aggression", hiding or sulking, or
failure to engage in feeding behavior, which will, of course, lead to
stress. Conscientious aquarists will always implement a stocking plan
for their aquarium that makes sense for the animals to be kept, and
takes into account the size of the tank, not to mention the ability of
the aquarist to provide for the animal's needs. A little advance
planning can pay big dividends down the line for future aquarium
inhabitants.

Conclusion

Marine Ich is certainly a dreaded disease; one that most
aquarists may have to contend with at some point during their hobby
"career". As frustrating as this disease may be to deal with,
I hope that the strategy outlined in this article provides you with the
encouragement you will need to attack it-and win! When you are battling
this illness, one of the most important things that you need to have is
a measure of patience! Since we are talking about a treatment protocol
that lasts a month or more, you need to "stick it out" and
stay with the program. As we have discussed, this treatment only works
if the aquarium is left fallow for a sufficient duration to affect a
cure. As with many worthwhile endeavors, the successful treatment of
this disease will take time, so remind yourself over and over again that the goal can be achieved, and that
you will be successful. Good luck!